A Tour of the Cell and Cell Signaling

Phagocytosis

forms a food vacuole, which fuses with a lysosome to digest molecules.

Nuclear envelope

encloses the nucleus, separating it from the cytoplasm

double membrane, each lipid bilayer has associated proteins

a pore complex helps the entry and exit of proteins, RNA, and macromolecules

DNA

is a nucleus that is bounded by a membranous nuclear envelope, membrane- bound organelles.

Mitochondria

sites of cellular respiration, a metabolic process that generates ATP.

Chromatin

unwound DNA, being used to direct protein synthesis

becomes distinct when the cells begin dividing because coils condense further and are thick enough to be distinguished under a microscope

Lysosome

membranous sac of hydrolytic enzymes that can digest macromolecules.

Chromosome

tightly packed DNA, during mitosis, not being used to direct protein synthesis.

Transmission electron microscope

focus a beam of electrons through the specimen.

Nucleolus

located in the nucleus and is the part of ribosomal RNA (rNA) synthesis.

Endoplasmic Reticulum

next to the nucleus, makes up more than half the total membrane system in eukaryotic cells

Cristae

increases the surface area for ATP synthesis.

Chloroplasts

found in plants and algae, are the sites of photosynthesis.

Plasmodesmata

opening between plant cells.

Organelles

membrane- enclosed compartments that are too small to be resolved by an times the size of the actual specimen.

Plasma membrane

selective barrier that allows sufficient passage of oxygen, nutrients, and waste to service every volume of the cell.

Centrioles

spindle fibers during animal cell division.

fats

Can hydrolyze proteins, polysaccharides, and nucleic acids.

Extracellular matrix of animal cells

support, adhesion, movement, regulation.

Bound ribosomes

make proteins for export and insertion into the membrane in the endoplasmic reticulum.

outside the nuclear envelope/ER

endomembrane system

The ________ is a complex and dynamic plate rin the cells compartmental organization.

Large central vacuole

found in mature plant cells, holds organic compounds and water.

Cell structure dictates

function.

Light microscope

visible light passes through and specimen and then through glass lenses, which manignity the image.

Gap junctions

opening between animal cells.

Rough ER

has bound ribosomes that make proteins for export, distributes transport vesicles (proteins surrounded by membranes), and a membrane factory for the cell.

Smooth ER

synthesizes lipids, stores calcium, detox

Small cells

are more efficient at moving materials in and out.

Contractile vacuoles

found in freshwater protists, pump excess water out of cells.

Ribosomes particles

made of ribosomal RNA and protein.

Plasma membrane

selective barrier that allows sufficient passage of oxygen, nutrients, and waste to service every volume of the cell

Free ribosomes

make proteins to be used within the cell in the cytosol
ex. enzymes to catalyze sugar breakdown

Bound ribosomes

make proteins for export and insertion into the membrane in the endoplasmic reticulum

Smooth ER

synthesizes lipids, stores calcium, detox

Rough ER

has bound ribosomes that make proteins for export, distributes transport vesicle (proteins surrounded by membranes), membrane factory for the cell

Phagocytosis

forms a food vacuole, which fuses with a lysosome to digest molecules

Contractile vacuoles

found in freshwater protists, pump excess water out of cells

Large central vacuole

found in mature plant cells, holds organic compounds and water

Centrioles

spindle fibers during animal cell division

Extracellular matrix of animal cells

support, adhesion, movement, regulation

Plasmodesmata

opening between plant cells

Gap junctions

opening between animal cells

Tight junctions

prevent leakage from water-tight barrier

Desmosomes

anchoring junctions

Cell wall

a rigid layer of polysaccharides enclosing the membrane of plant and prokaryotic cells

bacterial chromosome

located in the nucleoid
cytoplasmic structure, double-stranded DNA is coated with proteins

Flagella

locomotion organelles of some bacteria

Nuceloid

the region where a prokaryotic cell's DNA is located that is not enclosed by a membrane

Eukaryotic Cell

DNA is a nucleus that is bounded by a membranous nuclear envelope, membrane-bound organelles
Cytoplasm
Large and more effective
Protists, fungi, animals, and plants

Prokaryotic Cell

no nucleus or membrane-bound organelles
DNA in an unbound region called the nucleoid
Organisms of the domains Bacteria and Archaea

All cells have:

Plasma membrane
Double layer of phospholipids
Semifluid substance called cytoplasm
Chromosomes

Effective cells have

large surface area to volume ratio

Endomembrane System

Nuclear envelope
Endoplasmic reticulum
Golgi apparatus
Lysosomes
Vacuoles
Plasma membrane

lumen

internal compartment of the ER

Transport vesicles

Bud off a region of the rough ER to transitional ER and travel to the golgi and other destinations

Nuclear lamina

help maintain the nucleus because it has a net-like array of protein filaments by mechanically supporting the nuclear envelope

microvilli

long, thin projections on the surface of some cells

increases surface area

Nucleoli

where rRNA is produced

Ribosomes

made of rRNA and protein that are cellular compononets that carry out protein synthesis

glycoproteins

proteins covalently bonded to carbohydrates

Golgi Apparatus

products of the ER are modified and stored then sent to other destinations

they may remove or substitute monomers or membrane phospholipids

manufacture macromolecules

Autophagy

damaged organelle or small amount of cytosol is surrrounded by a double membrane and the lysosome fuses with the outer membrane. the cell can then be reused

Endosymbiont

cell living within another cell

Endosymbiont Theory

early ancestor and eukaryotic cells engulfed on oxygen using a non-photosynthetic prokaryotic cell

Secondary Cell Wall

often deposited in several lamination layers, strong and durable matrix that offers cell protection and support

Peroxisomes

contain enzymes that remove hydrogen atoms from certain ecules and transfer them to oxygen to create H2O2

Selectively Permeable

The plasma membrane allows some substances to enter the cell

Amphipathic

contains both a hydrophilic and hydrophobic regions

Fluid Mosaic Model

membrane is a fluid structure with a mosaic of various proteins embedded in it

As temperatures cool, membranes switch from

fluid to solid

Peripheral Proteins

bound to the surface of the membrane

Integral proteins

penetrate the hydrophobic core
span the membrane and are called- transmembrane

Aquqporin

door for water to pass through the plasma membrane

Channel proteins

allow passage of hydrophilic molecules through the plasma membrane

diffusion

the process in which there is movement of a substance from an area of high concentration of that substance to an area of lower concentration

facilitated diffusion

high to low through a protein

osmosis

facilitated diffusion of water

Hypertonic

Solute concentration is greater than that inside the cell, water leaves the cell

Hypotonic

Solute concentration is less than that inside the cell, water enters the cell

Osmolarity

concentration of a solution expresses as the total number of solute particles per liter

Tonicity

the ability of a solution to cause a cell to gain or lose water

Isotonic

solute concentration is the same as that inside the cell

Osmoregulation

control of water balance